There are good employees that can become detached or even become negative, bad apples when the culture and leadership of an organization fails for an extended period. Sure, one can uphold the examples of high character guys who bring their lunch pails everyday and toil under misguided organizations that squander good players talent and effort, because it's the right thing to do. But not all disgruntled employees are bad. Some are justified in their feelings. Diggs always struck me as a guy who gave all of himself to the game. In his early years, he made our defense go and you could see the difference when he was on the field. To draw correlation between him getting paid and his drop in performance is speculation on par with aligning Russell Wilson's decline with him getting with Ciara. I think Diggs just got fed up with what he saw as a franchise with no future, with a DC who was his leader and was unqualified, and a HC who was blind to the fact that the team was t going anywhere. To me, it's entirely reasonable for a guy who is putting his livelihood on the line in a sport where his career can be over in an instant to no longer feel inspired to go 200% full tilt, to make tackles in a system that was broken and not salvageable, regardless of how much effort he gave. Why would he? Sometimes it's the guys who in the end say 'F this BS, Im not going down for this nonsense ' who are the ones who - if they can correct their perspective and find their fire again- you want when the situation is rectified.
I think QDiggs is that guy. And more than that, like others have said, he isn't being brought here to save the D. He is a depth piece who brings in the field leadership and experience.